1. Field of the Invention
The present invention relates to a device for binding an article of footwear, such as a boot or a shoe, to a sports article, particularly to a gliding apparatus, such as a ski or a skate.
The invention also applies, in particular, to devices for binding a boot to a ski. In particular, it can be implemented in the design of bindings for cross-country skiing, alpine ski touring, Nordic ski touring or telemark skiing.
2. Description of Background and Relevant Information
An example of bindings of the aforementioned type is that of the cross country ski bindings marketed by Salomon S.A. under the trademark SNS Pilot® and described in the document EP 768 103 and in U.S. Pat. No. 6,017,050. In this type of binding, the boot is articulated by its front end about a transverse axis with respect to the ski, by means of a retaining system forming a jaw in which an articulation rod affixed to the boot sole is received.
The invention can also be applied in the context of a device such as described in the documents WO 00/13755, U.S. Pat. No. 6,499,761, EP 890 379, WO 96/37269, EP 914 844, U.S. Pat. No. 6,152,458, WO 01/93963, and U.S. patent application Publication No. 2003/0168830. In these types of bindings, the boot is retained on a connecting member connected to the remainder of the device by a mechanism that sets it, and the boot, on a particular path of movement between high and low positions.
The bindings to which the invention applies are to be distinguished from cable bindings of the types described, for example, in the documents U.S. Pat. No. 3,863,942, WO 99/02226, FR 2 363 341, and U.S. Pat. No. 3,844,575. These cable bindings are generally adapted for alpine skiing or telemark skiing. In either case, they include a stirrup arranged at the front, as well as a cable that is adapted to extend around the rear portion of the boot and to be tensioned in order to push the boot forward in support against the stirrup. Although the cable can possibly cause an elastic return effect, this effect is not the main effect desired, and it generally only occurs at the end the range of boot flexing. Indeed, the cable mainly acts as a boot retaining member within the retaining system constituted by the abutment and the cable. In this way, because the cable is primarily designed for its retention function, the return is generally arranged near the boot flexing point, which is approximately the center of rotation of the movement of the boot heel relative to the ski. As a result, because the return is arranged substantially in the area of this center of rotation, the cable only transmits a slight displacement to the spring, and the variation in this displacement with respect to the angular position of the heel varies only slightly; in addition, this variation is not truly controlled. In this way, the variation in the return force cannot be completely controlled. For certain positions of the boot, the return force can be almost zero; even negative. It has been noted that this control cannot be achieved when the retaining system and the elastic return system are not independent, as is the case in the prior art cable bindings in which, without the cable, the boot is no longer retained on the ski.